An application of remote sensing in hydrology - a case study in Malaysia

The fundamental objective of this study is to evaluate the feasibility of utilizing a set of remote sensing data to analyze the factors that contribute to the rate of runoff. The US Soil Conservation Service Technical Release 55 (SCS TR-55) hydrological model is used in this project. Nevertheless, cloud cover retricts the use of optical remotely sensed data in tropical regions such as Malaysia. Therefore, time series data of Landsat-5 TM are required in order to ensure the compatibility of data over time. The atmospheric correction is performed by using the atmospheric correction package in PCI's EASI/PACE V6.3. The radiometric correction process will not only correct the image data but also convert them to radiance or reflectance factor for quantitative analysis. Later, Gramm Schmidt Orthogonalisation (GSO) transformation is applied to distinguish the ground features in details. With this, a user can determine the curve number based on the classes that have been defined before. From the time series data also, percentage of forest change and urbanization that effect runoff can be easily obtained. In short, through the research of remote sensing data input in hydrology, certain applications have appeared to be promising areas for further testing of the operational usefulness of the new technology.